CN110242437B

CN110242437B - Combustion system of gasoline engine

Info

Publication number: CN110242437B
Application number: CN201910570772.1A
Authority: CN
Inventors: 慕金华
Original assignee: Chery Automobile Co Ltd
Current assignee: Chery Automobile Co Ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2021-12-28
Anticipated expiration: 2039-06-28
Also published as: CN110242437A

Abstract

The invention discloses a combustion system of a gasoline engine, wherein an air inlet channel on a cylinder cover is connected with a combustion chamber, the lower wall surface of the air inlet channel close to an air inlet valve seat is integrally a concave arc surface in the length direction of the air inlet channel, and the curvature center of the concave arc surface is positioned above the air inlet channel. Above-mentioned scheme is through the setting of concave cambered surface, makes the intake duct concave in the position that closes on the admission valve seat, and gas is when getting into the combustion chamber through the intake duct, and the gas that is located the downside can upwards move under the guide of concave cambered surface to make gaseous tumble strengthen, the effectual in-cylinder combustion efficiency that has improved has reduced oil consumption and particulate matter and has discharged.

Description

Combustion system of gasoline engine

Technical Field

The invention relates to the technical field of automobile engines, in particular to a combustion system of a gasoline engine.

Background

With the continuous development of science and technology, people have higher and higher requirements on energy conservation and environmental protection of automobiles, so that the direct injection supercharged gasoline engine in the cylinder is widely applied.

The air inlet passage of the prior direct injection gasoline engine is a diving type direct air passage, the tumble flow of the air passage is higher than that in the medium-large lift range, but is lower in the low lift range, and the idling or low-speed combustion of the engine is poor. In addition, the crown surface of the top surface of the piston guides fuel to the vicinity of the spark plug, when the fuel is sprayed to the crown surface of the piston with high heat, the fuel is easy to atomize, and under the working condition of cold start or low, medium speed and large load, a fuel oil film attached to the crown surface can generate incomplete combustion, so that the emission of hydrocarbon HC and particulate matters (PN) is increased.

Disclosure of Invention

The invention aims to provide a combustion system of a gasoline engine, which improves the combustion efficiency in a cylinder and reduces the oil consumption and the particulate matter emission.

In order to achieve the purpose, the invention adopts the technical scheme that: the utility model provides a gasoline engine combustion system, the intake duct on the cylinder cap is connected with the combustion chamber, and the intake duct closes on the lower wall face of intake valve seat department wholly to be the concave cambered surface on the length direction of intake duct, and the camber center of concave cambered surface is located the top of intake duct.

The beneficial effect of adopting above-mentioned technical scheme is: through the setting of concave cambered surface, it is recessed to make the intake duct in the position that closes on the admission valve seat, and gaseous when the intake duct gets into the combustion chamber, the gaseous meeting upward movement under the guide of concave cambered surface that is located the downside to make gaseous tumble strengthen, the effectual in-cylinder combustion efficiency that has improved has reduced oil consumption and particulate matter and has discharged.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural view of the cylinder head of the present invention;

fig. 3 is a schematic view of the structure of the piston top of the present invention.

Detailed Description

Referring to fig. 1-3, in a combustion system of a gasoline engine, an air inlet passage 10 on a cylinder cover is connected with a combustion chamber 20, the lower wall surface of the air inlet passage 10 close to an air inlet valve seat 30 is integrally a concave arc surface 11 in the length direction of the air inlet passage 10, and the curvature center of the concave arc surface 11 is positioned above the air inlet passage 10. According to the invention, the concave arc surface 11 is arranged on the air inlet 10, so that the air inlet 10 is suddenly concave at a position close to the air inlet valve seat 30, when the air enters the combustion chamber 20 through the air inlet 10, the air at the lower side moves upwards under the guidance of the concave arc surface, and a part of the air which enters the combustion chamber 20 from the lower edge of the air inlet valve originally moves to the upper edge of the air inlet valve to enter, so that strong tumble flow is formed, the combustion efficiency in the cylinder is effectively improved, and the oil consumption and the particulate matter emission are reduced. Specifically, the concave arc surface 11 on the lower wall surface of the air inlet duct 10 is a concave arc surface when viewed from the inside of the air inlet duct 10, and the smaller the curvature of the concave arc surface 11 is, that is, the larger the concave arc degree of the concave arc surface 11 is, the more obvious the tumble flow increase is.

Further, a concave table 21 is arranged on the chamber wall of the combustion chamber 20, which is close to the lower edge of the intake valve and far away from the symmetrical surface of the cylinder body, below the intake valve seat 30, the concave table 21 is arranged in a matched manner along the curved surface of the chamber wall of the combustion chamber 20, and the lower edge of the intake valve is located in a concave area of the concave table 21 during the small lift of the intake valve. Through the setting of concave station 21, when the valve is little lift, the lower limb of (air) intake valve is located the concave region of concave station 21, can understand that the lower limb of (air) intake valve is located concave station 21 height range in upper and lower direction like this for the clearance between (air) intake valve lower limb and the combustion chamber edge is very little, and intake resistance increases, leads to most gas from (air) intake valve upper limb direct impact cylinder, has strengthened the tumble ratio greatly. Specifically, the concave table 21 can be machined, machining precision is high, and collision between the intake valve and the chamber wall of the combustion chamber 20 can be effectively avoided.

Further, the concave platform 21 comprises an upper platform surface 211 and a side step surface 212, the upper platform surface 211 is integrally parallel to the plane of the intake valve seat 30, the side step surface 212 is located below the upper platform surface 211, and the side step surface 212 is integrally an arc surface matched with the circumferential profile of the lower edge of the intake valve. Specifically, the outline of the upper surface 211 is generally crescent-shaped, and the arc-shaped surface of the side step surface 212 is also crescent-shaped as a whole after being unfolded.

Further, the middle portion of the piston top surface 40 constituting the combustion chamber 20 is provided with a shallow concave area 41, the shallow concave area 41 includes a flat concave bottom 411 in the middle portion and steep walls 412 standing on both sides, and the bottom 411 is smoothly connected with the steep walls 412; the outer side of the steep wall 412 of the shallow concave area 41 is provided with a spherical curved surface 42, the intersecting line of the spherical curved surface 42 and the piston top surface 40 is an arc line and is adjacent to the peripheral contour line of the piston top surface 40 at intervals to form an annular plane 44, the intersecting line of the spherical curved surface 42 and the steep wall 412 forms a peak ridge line 45, the projection of the peak ridge line 45 in the direction vertical to the axial direction of the cylinder body is an arc line, the projection of the peak ridge line 45 on the projection plane passing through the axial core of the cylinder body is a curve with a high middle part and low two ends, one lower end is close to the symmetry plane of the cylinder body, and the other lower end is far away from the symmetry plane of the cylinder body. Wherein the flat concave bottom 411 means that the curvature of the bottom 411 is small, and the steep wall 412 means that the curvature of both side walls is large. Through the optimized design of the piston top surface 40, the spray guiding mode is improved, the strong tumble completely wraps the ejected oil beam, the oil mist is guided to the position near the spark plug under the movement of the air flow to form combustible mixed gas, the opportunity that fuel oil is in contact with the surfaces of the piston and the cylinder sleeve is greatly reduced, and the emission of HC and particulate matters is effectively reduced.

Further, a concave part 43 is arranged on the piston top surface 40 corresponding to the air inlet valve, and the lower edge of the air inlet valve is positioned in the concave part 43 at the maximum lift of the air inlet valve; the concave part 43 is integrally in an arc strip shape matched with the circumferential profile of the lower edge of the air inlet valve, one end of the concave part 43 is arranged close to the lowest end of the peak ridge line 45, and the other end of the concave part 43 is arranged close to the peripheral contour line of the piston top surface 40 at intervals. By the provision of the recess 43, the lower edge of the intake valve can be effectively prevented from colliding with the piston top surface 40 when the intake valve is at the maximum lift.

In the combustion system formed by the scheme, the maximum tumble ratio of the air inlet channel is improved by 28%, the tumble ratio of the compression stroke is improved by 59%, and the tumble is well kept; the peak value of the oil film of the cylinder barrel is reduced by 38 percent, and the peak value of the oil film of the top surface of the piston is reduced by 92 percent, thereby achieving the purpose of reducing the oil film, namely reducing the oil consumption and improving the emission of particulate matters.

Claims

1. The utility model provides a gasoline engine combustion system, intake duct (10) on the cylinder cap are connected with combustion chamber (20), its characterized in that: the lower wall surface of the air inlet channel (10) close to the air inlet valve seat (30) is integrally a concave cambered surface (11) in the length direction of the air inlet channel (10), and the curvature center of the concave cambered surface (11) is positioned above the air inlet channel (10);

a concave table (21) is arranged on the chamber wall of the combustion chamber (20) which is close to the lower edge of the air inlet valve and far away from the symmetrical surface of the cylinder body below the air inlet valve seat (30), the concave table (21) is arranged along the curved surface trend of the chamber wall of the combustion chamber (20) in a matching way, and the lower edge of the air inlet valve is positioned in the concave area of the concave table (21) when the valve has small lift; the concave platform (21) comprises an upper platform surface (211) and a side step surface (212), the upper platform surface (211) is integrally parallel to the plane where the air inlet valve seat (30) is located, the side step surface (212) is located below the upper platform surface (211), and the side step surface (212) is integrally an arc-shaped surface matched with the circumferential profile of the lower edge of the air inlet valve.

2. The gasoline engine combustion system of claim 1, wherein: the middle part of the piston top surface (40) forming the combustion chamber (20) is provided with a shallow concave area (41), the shallow concave area (41) comprises a flat concave bottom (411) positioned in the middle part and steep walls (412) standing on two sides, and the bottom (411) is smoothly connected with the steep walls (412).

3. The gasoline engine combustion system of claim 2, wherein: spherical curved surface (42) has been arranged in the outside of the cliff (412) of shallow concave region (41), spherical curved surface (42) and piston top surface (40) intersecting line are the pitch arc and its peripheral contour line with piston top surface (40) is close to the interval and arranges and constitute cyclic annular plane (44), spherical curved surface (42) and cliff (412) intersecting line constitute peak crest line (45), peak crest line (45) is the arc line in the projection of perpendicular to cylinder body axial direction, peak crest line (45) projection on the plane of projection of crossing the cylinder body axle core is middle height, the curve that both ends are low and one of them low end is close to the cylinder body plane of symmetry, the cylinder body plane of symmetry is kept away from to another low end.

4. The gasoline engine combustion system of claim 1, wherein: a recess (43) is provided in the piston top surface (40) corresponding to the intake valve, and the lower edge of the intake valve is located in the recess (43) at the maximum valve lift.

5. The gasoline engine combustion system of claim 4, wherein: the concave part (43) is integrally in an arc strip shape matched with the circumferential profile of the lower edge of the air inlet valve, one end of the concave part (43) is arranged close to the lowest end of the crest line (45), and the other end of the concave part is arranged close to the peripheral profile line of the piston top surface (40) at intervals.